Jack



E. A. DORMAN.

JACK.

APPLICATION FILED MAY 22'. 1919.

2 SHEETSSHEET I.

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llNcglzioR I E.A.'DORMAN.

JACK.

APPLICATION FILED MAY 27, 1919.

1,367,307. Pawhwa Feb. 1,1921.

2 SHEETS-SHEET 2.

liiili ATT oRN Y UNITED STATES PATENT OFFICE.

EDWARD A. DOBMAN, OF NEW YORK, N. Y., .ASSIGNOR T JOHN Hi DORMAN, OF NEWYORK, N.'Y.

JACK.

Specification of Letters Patent.

Patented Feb. 1, 1921.

Application filed May 27, 1919. Serial No. 300,162.

To all w 710m it may concern 1 Be it known thatI, EDWARD A. DoRMAN, acitizen of the United States, and a resident of New York city, in thecounty of New York and State of New York have invented certain new anduseful lmprove ments in J acks of which the following is aspecification.

The invention relates in general to a lifting jack of the type designedto constitute an automobile accessory and which is usually provided witha horizontally extending actuating lever for actuating the liftingmechanism and further the invention relates to that type of lifting acksin which the manipulation of a reverse controlling mechanism permit theuse of the same mechanism for effecting either the raising or loweringof the lifting element of the jack.

The primary object of the invention is to provide a simple form of jackdesigned to respond to the requirement for a light, compact and powerfuljack which will develop unusual power and which can be positivelyactuated in either its lifting or lowering movement and will functionindependently of any careless actuation on the part of the operator.

Broadly, this object is attained by pro viding a control for theactuating mechanism in which the several operable parts areindependently spring controlled so as to function independently of themovement of the actuating lever into its limiting position.

Another object of the invention is to provide a simple form of jackwhich will eco' nomically utilize the muscular effort imposed upon theactuatinglever and trans mit the same through a system of compoundlevers to eifect a powerful raising or lowerin movement of the liftingelement.

his object is attained broadly, first by mounting the actuating lever inspaced relation to the lifting ratchet and causing said lever and theratchet feeding pawl to eonstitute in effect a compound leveragedesigned to exert a powerful turning movement on the ratchet.

A still further object of the invention is to provide an organization ofparts designed so that the movement of the lifting element into alimiting position will automatically disconnect the actuating lever fromth li ting eleme t s t t y 1 tinned movement of the actuating lever willnot affect the position of the liftmg element or deleteriously imposestrains on the lifting mechanism.

Variousother objects and advantages of the invention will be in partobvious from an inspection of the accompanying drawin and in part willbe more fully set forth in the followlng particular description of oneform of mechanism embodying my invention, and the invention alsoconsists in certain new and novel features of construction andcombination of parts hereinafter set forth and claimed.

In the accompanying drawings Figure 1 is a view in side elevation of apreferred embodiment of the invention with the front of the casingremoved and parts broken away to show internal construction and with thelifting mechanism in position to raise the lifting element;

Fig. 2 is a view similar to Fig. 1 with the lifting mechanism inposition to control the lowering movement of the lifting element andwith the actuating lever in its fully raised position;

Fig. .3 is a view similar to Fig. 2 with certain parts omitted and withthe actuating lever in its fully lowered position;

Fig. 4: is a view similar to Fig. 1 withthe parts in advance oftheratchet removed and showing the lifting element locked in its fullyraised position; and

Fig. 5 is a horizontal sectional view taken on the line 5-5 of Fig. llooking downwardly as indicated by the arrow.

In the following description and in the claims, parts will be identifiedby specific names for convenience of expression but they are intended tobe as generic in their application to similar parts as the art willpermit.

In the drawings there is shown a standard provided with a casing 11 inwhichis slidably mounted a lifting element in the form of a rack bar 12which carries the usual swivel head 13. A ratchet shaft 1 1% is mountedin the casing for free rotary movement about a horizontal axis and isprovided with a pinion 15 constantly in mesh with the teeth 16 of therack bar 12. This shaft has a relatively large one-way ratchet 16 fixedto one end thereof. An actuating lever 17 is fulcrumed to the pin 18carried by the casing and is positioned to the outside of the ratchetand disposed vertically below the axis of rotation of the shaft 14. Onearm of the lever extends exteriorly of the casing and constitutes ahandle 19 by means of which the device is actuated. The pin 18constitutes a support for a retaining pawl 20, normally held inengagement with the teeth of the ratchet by a spring 21, and which actsto hold the ratchet from forward rotation responsive to the load on thelifting element.

The other arm 22 of the lever 17 1s relatively short, dependsdownwardly' and extends slightly forwardly from the axis of the pin 18and has a relatively long upstanding feeding pawl 23 pivoted thereto foroscillation about a pivoting pin 24. A light-acting spring 25 normallyacts upon the feeding pawl to hold the same in operative engagement withthe teeth of the ratchet as shown more particularly in Fig. 1.

In the normal operation of raising the load the ratchet wheel will bemoved clockwise by the downward movement of the lever acting through thefeeding pawl and the retaining pawl will hold the ratchet from reversemovement responsive to the load during the dwell of the actuating leverand during its upward or idle stroke.

Means are provided for controlling the lowering movement of the rack 12under the influence of the loadand for this purpose a latch 26 isoperatively associated with the feeding pawl and retaining pawl tosuecessively withdraw the same from the path of movement of the ratchetteeth in timed sequence to the movement of the actuating lever 17 Thelatch 26 is substantially U-s'haped with its upper end pivoted to a pin27 carried by the casing and, when free, is caused toswing'anti-clockwise under the tension of a coiled spring 28 actingthereon to swing the lower end 29 toward the two pawls. It is understoodthat the spring 28 1s stronger than either of the springs 21 or 25. Theupper side of the end 29 is provided with a pair of recessed cam faces30 and 31 each designed to engage a pin 32 extending laterally from aposition in the I feeding pawl adjacent its ratchet engaging point 33.Similarly the lower side of the end 29 is provided with a cam face 34designed in the actuation of the device to engage a pin 35 on theretaining pawl to move the same into an inoperative position.

For the purpose of holding the latch in an operative position so as topermit the feeding and retaining paWls to function normally to lift therack 12, there is provided a lifting and locking device in the form of alever 36 having one end 37 extending exteriorly of the casing andconstituting a handle for shifting the. device. The inner end of thelever is provided with a notch 38 designed to engage under a pin 39carried by the latch and so arranged that the shifting of the latch intothe position shown in Fig. 1 will raise the latch 26 into theinoperative position spaced from the pins 32 and 35 as shown in Fig. 1.

For the purpose of moving the feeding pawl into its inoperative positionwhen the rack 12 has reached the limit of its upward movement, the lowerend of the rack is provided with a pin 40 extending laterally therefromand designed to engage the under side of an inturned finger 41constituting an extension from the upper end of a locking cam 42. Thiscam is fulcrunied on a pin 43 and is provided on one side with a camface 44 designed to engage the pin 32 to swing the feeding pawl 23 fromthe operative position shown in Fig. 1 into a position with the point 33in spaced relation to the teeth of the ratchet. A spring 45 normallyacts on the cam 42 to hold the face 44 thereof in spaced relation. tothe pin 32 of the actuating lever 17, the manual force exerted on theouter end of the lever will act through the small power arm between theaxis of rotation of the pins 18 and 251-. This long work arm and shortpower arm thus formed reduce the length of resulting movement and thuscorrespondingly increasing the resultant force. This short length butpowerful force acts upwardly through the feeding pawl to advance theratchet over a short rotary arch, as is well known in devices of thischaracter. In this connection the device features the square fit of thepoint 33 against the engaged face of the ratchet during the entire swingof the pawl. It is appreciated that any ratchet feeding movement of theactuating lever will have no effect upon the retaining pawl, as thisretaining pawl is pivoted concentrically with the axis of oscillation ofthe lever. This retaining pawl under these conditions will act to holdthe ratchet against reverse movement as is usual in such construct-ionsand the fulcrum pin thus acts to provide a support for the retainingpawl.

Assuming that there is a load acting on the rack 12 and that it isdesired to grad ually lower the load under control of the operator. Thehandle 37 is raised from the position shown in F ig. 1 into thepositions shown in Figs. 2 and 3, thus removing the locking device fromthe latch and permitting the powerful spring 28 to act on the latch andswing the same forwardly into llll mgeemov the position shown in eitherFigs. 2 or s i depending upon the position of the actuat- Cir ing lever.Assuming first, that the lever is in the raised position shown inFig. 2,it will be noted that the latch has swung forward until the cam.depression 30 is in engagement with the pin 32. The latch acts under theforce of the spring 28 to :move the feeding pawl positively into s acedrelation to the ratchet teeth. In this position, however, the cam face34 is in s aced relation to the pin thus permitting the retaining pawlto remain in its holding engagement with the ratchet. As the actuatinglever is lowered from the position shown in Fig. 2 toward the positionshown in Fig. 3, the cam face 34 is caused to engage the pin 35 andremove the retaining pawl from its holding engagement with the ratchetas shown in Fig. .3. The loweringof the actuating lever will at the sametime raise the feeding pawl and its spring 25 will act thereon to swingthe pin 32 from the recess 30 into the upper recess 31 and the point 33will be thus raised into engagement with the ratchet teeth but in spacedrelation to the flat face 46 of the next succeeding ratchet tooth inadvance of the point. This will allow the weight to react through thepinion 15 and move the ratchet a distance lessthan the length of oneradial tooth distancathus permitting the lowering of the rack for acorresponding distance. This loweri movement is accordingly undercontrol 0 the operator as he lowers the actuating lever and the powerfulleverage effect of the device herein disclosed is utilized to ease thefall of the weight even over this small distance. The cam surfaces areso designed that as the actuating lever is again moved toward the raisedposition shown in Fig. 2, the retaining pawl is promptly released andpositioned by its spring into holdin engagement with the ratchet priorto tie with drawing of the feeding pawl into the inoperative positionshown in F iv. 2.

As the lifting rack approac es the limit of its movement the pin liftsthe latch 42 and causes the cam face 44 to engage the pin 32 and thusmoves the feeding pawl into an inoperative position and theraok 12 isthus locked against any further upward movement and against anyaccidental lowering movement which might be caused by the weight imposedthereon.

By means of a device of this character it is appreciated that the latchis at all times, except when locked in the position shown in Fig. 1,under the action of its own spring 28 which has a tendency to engage thefeeding pawl and is not dependent for its actipn upon the movement ofthe lever into a limiting position or into engagement with the latch. VThe device Wlll function even though the actuating lever is not movedpawl actuated by the into its limiting position and will function evenin the hands of a careless operator. If

been reducedto a minimum but an effective leverage movement has beenattained with the usual multiplicity of moving parts.

While I have shown and described, and

have pointed out in the annexed claims, certain novel features of myinvention, it will be understood that various omissions, substitutionsand changes in the form and details of the device illustrated and in itsoperation may be made b 1 those skilled in the art without departing romthe spirit of the invention.

Having thus described my invention, I claim:

1. In a device of the class described, the combination with a liftingelement, of an operating mechanism for lifting said element, saidmechanism including an actuating ratchet, an operatin lever, a feedingever to feed the ratchet in its element lifting direction and meanscontrolled by the movement of the element into its fully-lifted positionand movable into engagement with said pawl to move the same into aninoperative position. said means including a member sup ortcdindependently of both the lifting e ement and the pawl.

2. In a lifting jack, the combination of a lifting element, an actuatingmechanism for moving the element toward a limiting position and meanscontrolled by the movement ofsaid element into its limiting position forautomatically disconnectin the mechanism and element including an eement supported independentl of both the lifting element and the paw 3.In a liftin jack, the combination of a base member, a ifting element, anactuating mechanism for moving the element toward a limiting positionand means controlled by the movement of said element into its limitingposition for automatically disconnecting the mechanism and element, saidmeans in cluding a member mounted to swing about a fulcrum fixed withrelation tothe base member. p i

4. In a lifting jack, the combination of a lifting element, an actuatingmechanism for moving the element toward a limiting position including aratchet mounted for rotary movement and an operating pawl therefor andmeans controlled by the movement of said element into its limitinposition for automatically disconnecting t e mechanism and element.

5. In a lifting jack, the combination of a lifting element, an actuatingmechanism for moving the element toward a limiting position and meanscontrolled by the movement of said element into its limiting positionfor automatically disconnecting the mechanism and element and meanscontrolled by the initial movement of said element away from, saidlimiting position for automatically restoring the operative connectionbetween said element and said actuating mechanism.

6. In a lifting jack, the combination of a lifting element embodying arack, a shaft provided with apinion meshing with said rack 'and'with aone-way ratchet, an operating lever fulcrumed in oflset relation to theaxis of rotation of the ratchet and provided with a feeding pawl adaptedto engage the ratchet to positively operate the lifting element, apendulous latch having an upper cam surface adapted to engage thefeeding pawl, a spring for moving said latch into operative engagementwith said pawl, said,

cam surface and said pawl being disposed in lapped relation whereby theoperating lever will shift the pawl relative to the latch thereby tocause the pawl to alternately engage and disengage the ratchet andcontrol the movement of the lifting element in the reverse direction anda cam engaged by said rack and in turn acting on said feeding pawl tomove the same into an inoperative position. i

7. In a lifting jack, the combination of a lifting element, actuatingmechanism therefor including a ratchet wheel, an oscillating bell crankhaving a relativelysliort arm, fulcrumed vertically below the axis oftheratchet wheel, a lifting pawl carried by the free end of the short arm,a holding pawl pivoted on the lever fulcrum, and a pendulous latchpivotingat its upper end and with its lower free end normally positionedbetween the ratchet' engaging ends of the two pawls, coacting surfaceson the pawls and the said free end, and a spring normally tending tobring said coacting surfaces into operative relationship and a membercoacting with said latch to move said surfaces out of operativerelationship. i

8. In a lifting jack, the combination with a lifting mechanism includinga vertically movable lifting bar and a power multiplying connection foractuating the bar, said mechanism including a one-way ratchet, astrain-receiving fulcrum pin positioned below the ratchet and insubstantial vertical alinement with the axis of rotation thereof, anactuating lever pivoted to said fulcrum pin, a relatively longupstanding feeding pawlpivoted to the lever close to the fulcrum pin forpositively actuating the ratchet ina direction to act through the powermui tiplying connection to raise the bar, a relatively short retainingpawl pivotally mounted on said fulcrum pin to transmit the strains fromthe ratchet directly to the fixed fulcrum pin, said retaining pawlextending from the fulcrum in a direction substantially tangent to thepath of movement of the teeth on the ratchet and engaging the teeth onthe underside of the ratchet for preventing reverse movement of theratchet when acted upon by the load on the lifting bar.

9. In a lifting jack, the combination with a lifting bar and mechanismfor actuating the same, said mechanism including a oneway ratchetmounted for rotary movement about a horizontal axis, a fulcrum pinpositioned vertically below said axis, an actuating lever pivoted tosaid pin and having a relatively short arm extending horizontally fromthe fulcrum pin, a relatively long actuating pawl pivoted to said shortarm and ex tending upwardly normally to engage the ratchet teeth a shortdistance below a horizontal line passing through the axis of ro tationof the ratchet whereby the pawl is raised bodily in a substantiallyvertical line tangent to the periphery of the ratchet as the pivotedlower end is rocked over a small angle on opposite sides of the verticalline through the axis of the ratchet and lever fulcrum.

10. In a lifting jack, the combination of a one-way ratchet, a loadlifting member actuated-thereby, a fulcrum pin mounted vertically belowthe axis of the ratchet, an actuating lever pivotally mounted on saidpin, a relatively long feeding pawl having one end pivoted to the leverrelatii ely close to its fulcrum, extending upwardly therefrom andprovided with an engaging point for fitting against the teeth of theratchet on one side thereof, said pawl having a substantially straightline upward movement during the actuation of the ratchet in thedirection to raise the lifting member.

Signed at New York city, in the county of New York and State of New Yorkthis 15th day of lWay, A. D. 1919.

EDlVAR-D A. DORB'IAN.

